C# 在winform中查找控件

/// <summary>
/// 在winform中查找控件
/// </summary>
/// <param ></param>
/// <param ></param>
/// <returns></returns>
private System.Windows.Forms.Control findControl(System.Windows.Forms.Control control, string controlName)
{
    Control c1;
    foreach (Control c in control.Controls)
    {
        if (c.Name == controlName)
        {
            return c;
        }
        else if (c.Controls.Count > 0)
        {
            c1 = findControl(c, controlName);
            if (c1 != null)
            {
                return c1;
            }
        }
    }
    return null;
}

//调用

for (int i = 1; i <= 30; i++)
{
    string _box = "b" + i.ToString();
    TextBox tb = (TextBox)this.findControl(groupBox2, _box);
    tb.Text = i.ToString();
}